Retrieve HWLOC API version from hwloc.h header

The FindLIBHWLOC.cmake module previously used the config.h header
to retrieve the HWLOC library version. This header was not always
present depending on how the library was distributed. To address
this issue, we now rely on the HWLOC API version retrieved from
hwloc.h, the main HWLOC library header.

Co-authored-by: Łukasz Plewa <[email protected]>
Co-authored-by: Krzysztof Filipek <[email protected]>

Author: 3 people

cmake/FindLIBHWLOC.cmake

@@ -14,28 +14,28 @@ find_file(LIBHWLOC_HEADER NAMES hwloc.h)
 get_filename_component(LIBHWLOC_INCLUDE_DIR ${LIBHWLOC_HEADER} DIRECTORY)
 set(LIBHWLOC_INCLUDE_DIRS ${LIBHWLOC_INCLUDE_DIR})
 
-if(LIBHWLOC_INCLUDE_DIR)
-    if(EXISTS "${LIBHWLOC_INCLUDE_DIR}/hwloc/autogen/config.h")
-        file(
-            STRINGS "${LIBHWLOC_INCLUDE_DIR}/hwloc/autogen/config.h"
-            LIBHWLOC_VERSION
-            REGEX
-                "#define[ \t]HWLOC_VERSION[ \t]\"([0-9]+.[0-9]+.[0-9]+(rc[0-9])?)(-git)?\""
-        )
-        string(
-            REGEX
-            REPLACE
-                "#define[ \t]HWLOC_VERSION[ \t]\"([0-9]+.[0-9]+.[0-9]+(rc[0-9])?)(-git)?\""
-                "\\1"
-                LIBHWLOC_VERSION
-                "${LIBHWLOC_VERSION}")
-    else()
-        message(
-            WARNING
-                "LIBHWLOC_INCLUDE_DIR found, but header with version info is missing"
-        )
-    endif()
-endif()
+set(HWLOC_VERSION_CODE
+    "
+#include <stdio.h>
+#include <stdlib.h>
+#include \"hwloc.h\"
+
+void main(int argc, char** argv) {
+    unsigned LIBHWLOC_API_PATCH = HWLOC_API_VERSION & 0xFF;
+    unsigned LIBHWLOC_API_MINOR = (HWLOC_API_VERSION >> 8) & 0xFF;
+    unsigned LIBHWLOC_API_MAJOR = (HWLOC_API_VERSION >> 16) & 0xFF;
+    printf(\"%d.%d.%d\", LIBHWLOC_API_MAJOR, LIBHWLOC_API_MINOR, LIBHWLOC_API_PATCH);
+}")
+
+set(HWLOC_VERSION_CODE_FILENAME "hwloc_get_version.c")
+file(WRITE "${CMAKE_BINARY_DIR}/${HWLOC_VERSION_CODE_FILENAME}"
+     "${HWLOC_VERSION_CODE}")
+
+try_run(
+    HWLOC_RUN_RESULT HWLOC_COMPILE_RESULT ${CMAKE_BINARY_DIR}
+    "${CMAKE_BINARY_DIR}/${HWLOC_VERSION_CODE_FILENAME}"
+    CMAKE_FLAGS "-DINCLUDE_DIRECTORIES=${LIBHWLOC_INCLUDE_DIR}"
+    RUN_OUTPUT_VARIABLE LIBHWLOC_API_VERSION)
 
 if(WINDOWS)
     find_file(LIBHWLOC_DLL NAMES "bin/hwloc-15.dll" "bin/libhwloc-15.dll")
@@ -48,18 +48,19 @@ if(LIBHWLOC_LIBRARY)
     message(STATUS "    LIBHWLOC_LIBRARIES = ${LIBHWLOC_LIBRARIES}")
     message(STATUS "    LIBHWLOC_INCLUDE_DIRS = ${LIBHWLOC_INCLUDE_DIRS}")
     message(STATUS "    LIBHWLOC_LIBRARY_DIRS = ${LIBHWLOC_LIBRARY_DIRS}")
-    message(STATUS "    LIBHWLOC_VERSION = ${LIBHWLOC_VERSION}")
+    message(STATUS "    LIBHWLOC_API_VERSION = ${LIBHWLOC_API_VERSION}")
     if(WINDOWS)
         message(STATUS "    LIBHWLOC_DLL_DIRS = ${LIBHWLOC_DLL_DIRS}")
     endif()
 
     if(LIBHWLOC_FIND_VERSION)
-        if(NOT LIBHWLOC_VERSION)
+        if(NOT LIBHWLOC_API_VERSION)
             message(FATAL_ERROR "Failed to retrieve libhwloc version")
-        elseif(NOT LIBHWLOC_VERSION VERSION_GREATER_EQUAL LIBHWLOC_FIND_VERSION)
+        elseif(NOT LIBHWLOC_API_VERSION VERSION_GREATER_EQUAL
+               LIBHWLOC_FIND_VERSION)
             message(
                 FATAL_ERROR
-                    "    Required version: ${LIBHWLOC_FIND_VERSION}, found ${LIBHWLOC_VERSION}"
+                    "    Required version: ${LIBHWLOC_FIND_VERSION}, found ${LIBHWLOC_API_VERSION}"
             )
         endif()
     endif()